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A Ruin Model with Compound Poisson Income and Dependence Between Claim Sizes and Claim Intervals

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Acta Mathematicae Applicatae Sinica 2015年第2期31卷 445-452页

作者： yuan-yuan hao Hu YANG Department of Statistics and Actuarial Science Chongqing University College of Mathematics Chongqing Normal University

We consider a ruin model with random income and dependence between claim sizes and claim intervals. In this paper, we extend the determinate premium income into a compound Poisson process and assume that the distribution of the time between two claim occurrences depends on the previous claim *** the premium size is exponentially distributed, the（Gerber-Shiu） discounted penalty functions is ***, we consider a similar model.

关键词： discounted penalty function laplace transform ruin model dependence

A Ruin Model with Random Income and Dependence between Claim Sizes and Claim Intervals

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Acta Mathematicae Applicatae Sinica 2010年第4期26卷 625-632页

作者： Hu Yang yuan-yuan hao College of Mathematics and Statistics Chongqing UniversityChongqing400030China

In this paper,we consider a generalization of the classical ruin model,where the income is random and the distribution of the time between two claim occurrences depends on the previous claim *** model is more appropriate than the classical ruin *** expression for the generating function of the Gerber-Shiu expected discounted penalty function are derived.A similar model is ***,the result are showed by two examples.

关键词： Ruin model expected discounted penalty function dependence ruin probability

An Improved RPL Algorithm for Low-Power and Lossy Networks

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China Communications 2023年第1期20卷 140-152页

作者： Yanan Cao hao yuan Tianjin Key Laboratory of Wireless Mobile Communications and Power Transmission Tianjin Normal UniversityTianjin 300387China Chinese People’s Liberation Army Unit 61846 Zhuozhou 07250China

The routing protocol for low-power and lossy networks(RPL),standardized by Internet Engineering Task Force(IETF),is mainly designed to use for Low-power and Lossy Networks(LLNs).To solve the problems of several important routing metrics are not evaluated,the optimal path may contain long single hop links,lack of scientific multi-routing metrics evaluation method and mechanism to balance the parent child number(especially the parent with one hop away from root),this paper proposes an improved RPL algorithm for LLN(I-RPL).First of all,we propose the evaluated routing metrics:child number of parent,candidate parent number,hop count,ETX and energy consumption ***,we improve the path ETX calculation method to avoid selecting optimal path containing long single hop *** we design a novel lexical method to synthetically evaluate candidate ***,based on the evaluation results of candidate parents,we design a novel objective function and a new calculation node rank method which can also be used for selecting the optimal ***,evaluation results show that I-RPL outperforms ETXOF and several other improvements in terms of packet delivery ratio,latency,etc.

关键词： routing protocol RPL routing metric lexical method objective function

Environmental Adaptive Control of a Snake-like Robot With Variable Stiffness Actuators

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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 745-751页

作者： Dong Zhang hao yuan Zhengcai Cao IEEE College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China

This work investigates adaptive stiffness control and motion optimization of a snake-like robot with variable stiffness actuators. The robot can vary its stiffness by controlling magnetorheological fluid(MRF) around actuators. In order to improve the robot's physical stability in complex environments, this work proposes an adaptive stiffness control strategy. This strategy is also useful for the robot to avoid disturbing caused by emergency situations such as collisions. In addition, to obtain optimal stiffness and reduce energy consumption, both torques of actuators and stiffness of the MRF braker are considered and optimized by using an evolutionary optimization algorithm. Simulations and experiments are conducted to verify the proposed adaptive stiffness control and optimization methods for a variable stiffness snake-like robots.

关键词： Adaptive control snake-like robot variable stiffness

Interfacial properties of black phosphorus/transition metal carbide van der Waals heterostructures

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Frontiers of physics 2018年第3期13卷 91-99页

作者： hao yuan Zhenyu Li Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei 230026 China

Owing to its outstanding electronic properties, black phosphorus （BP） is considered as a promis- ing material for next-generation optoelectronic devices. In this work, devices based on BP/MXene （Zrn＋1CnT2, T = O, F, OH, n = 1, 2） van der Waals （vdW） heterostructures are designed via first-principles calculations. Zrn＋1CnW2 compositions with appropriate work functions lead to the for- mation of Ohmic contact with BP in the vertical direction. Low Schottky barriers are found along the lateral direction in BP/Zr2CF2, BP/Zr2CO2H2, BP/Zr3C2F2, and BP/Zr3C2O2H2 bilayers, and BP/Zr3C202 even exhibits Ohmic contact behavior. BP/Zr2CO2 is a semiconducting heterostructure with type-II band alignment, which facilitates the separation of electron-hole pairs. The band struc- ture of BP/Zr2CO2 can be effectively tuned via a perpendicular electric field, and BP is predicted to undergo a transition from donor to acceptor at a 0.4 V/A electric field. The versatile electronic prop- erties of the BP/MXene heterostructures examined in this work highlight their promising potential for applications in electronics.

关键词： BP/MXene Schottky barrier type-Ⅱ band alignment

Monolithic macroporous catalysts—a new route for miniaturization of water-gas shift reactor

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Journal of Natural Gas Chemistry 2009年第4期18卷 436-440页

作者： hao Liang yuan Zhang yuan Liu Department of Catalysis Science and Technology School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

Monolithic macroporous Pt/CeO2/Al2O3 catalysts were prepared using concentrated emulsions synthesis route, and the obtained samples were characterized with SEM, TG, TEM, XRD and TPR techniques. These monolithic catalysts were applied to water gas shift （WGS） reaction in reformed gases. The SEM and TEM results indicated that the monoliths possessed macroporosity, and that the platinum particles homogeneously dispersed on the supports with the particle size in the range of 1-2 nm. The reducibility of the catalysts was characterized by TPR method, and it was shown that the monolithic PtOx/CeO2/Al2O3 exhibited the similar reducibility property to that of the particle PtOx/CeO2 reported in literatures. The CO conversion over the monolithic catalysts is higher than that over micro-reactor catalysts for WGS reaction in the reformed gases conditions, indicating that the monolithic macroporous catalysts is a potential new route for miniaturization of WGS reactor.

关键词： macroporous monolith miniaturization water gas shift platinum

Formation of Liquid Pools Entrapped within Solid Grains of ZA27 Alloys during Partial Remelting

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Journal of Materials Science & Technology 2002年第6期18卷 481-483页

作者： Tijun CHEN yuan hao Jun SUN State Key Laboratory of Mechanical Behavior for Materials Xi'an Jiaotong UniversityXi'an 710049China School of Materials Science and Engineering Gansu University of TechnologyLanzhou 730050China

The investigations were performed into the formation processes of liquid pools entrapped within solid grains of three ZA27 alloys, produced respectively by either grain refinement, or traditional permanent casting or mechanical stirring, during partial remelting at semisolid temperature of 460℃. The results show that the rapid coalescence of primary grains due to merging of secondary arms during the initial stage of partial remelting is the main cause for the formation of the entrapped liquid pools. This coalescence resulted in that a high quality of eutectics, especially the 77 phase, was entrapped within the grains, and then remelted to form liquid pools during the subsequent heating. In addition, the growth of the η phase decomposed from the primary α' phase and β phase and the subsequent remelting is another cause for the refined and permanent mould casting alloys. Furthermore, the agglomeration of the solid grains also resulted in the entrapment of liquid in the interior of grains.

关键词： Thixoforming ZA27 alloy Partial remelting Microstructure

Semi-Discrete and Fully Discrete Mixed Finite Element Methods for Maxwell Viscoelastic Model of Wave Propagation

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Advances in Applied Mathematics and Mechanics 2022年第2期14卷 344-364页

作者： hao yuan Xiaoping Xie School of Mathematics Sichuan UniversityChengduSichuan 610064China

Semi-discrete and fully discrete mixedﬁnite element methods are consid-ered for Maxwell-model-based problems of wave propagation in linear viscoelastic *** mixedﬁnite element framework allows the use of a large class of exist-ing mixed conformingﬁnite elements for elasticity in the spatial *** the fully discrete scheme,a Crank-Nicolson scheme is adopted for the approximation of the temporal derivatives of stress and velocity *** estimates of the semi-discrete and fully discrete schemes,as well as an unconditional stability result for the fully discrete scheme,are *** experiments are provided to verify the theoretical results.

关键词： Maxwell viscoelastic model mixedﬁnite element semi-discrete and fully discrete error estimate stability.

Pancreatic triglyceride lipase is involved in the virulence of the brown planthopper to rice plants

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Journal of Integrative Agriculture 2020年第11期19卷 2758-2766页

作者： yuan Long-yu hao yuan-hao CHEN Qiao-kui PANG Rui ZHANG Wen-qing State Key Laboratory of Biocontrol/School of Life Sciences SunYat-sen UniversityGuangzhou 510275P.R.China

The brown planthopper(BPH),Nilaparvata lugens,an important rice insect pest,can enhance its virulence to BPH-resistant rice within as short a span as several ***,we cloned a pancreatic triglyceride lipase(PTL)gene(NlPTL)in ***,and found that its mRNA level was higher in the high virulence population(fed on variety Rathu Heenati,P-RH)than in the low virulence population(fed on variety Taichung Native 1,P-TN1).Knocking down NlPTL caused BPH individuals to spend more time in non-penetration and the pathway phases and less time feeding on the phloem of rice plants;these changes consequently decreased food intake,lipid content,survival rate,and fecundity in the *** findings reveal for the first time that PTL in BPH is involved in its virulence to rice plants.

关键词： pancreatic triglyceride lipase Nilaparvata lugens virulence rice lipid